1. Field of the Invention
The present invention relates to a rolling bearing lubricated with oil. More specifically, the present invention relates to a rolling bearing lubricated with oil which is filtered through filters.
2. Description of Related Art
Power transmission devices such as transmissions, differentials and reduction gears in automobiles and various types of construction machines, or travel units including these devices, include rolling bearings.
Some of these types of travel units have a structure in which rolling bearings are lubricated with the same oil used to lubricate the power transmission devices.
However, the oil filled inside the casings of the power transmission devices such as transmissions, differentials and reduction gears contains relatively large amount of foreign substances, such as gear wear debris (iron dust and the like). If the foreign substances contained in the oil get inside the rolling bearing, the foreign substances between the raceway surfaces of the rolling bearing and the rolling contact surfaces of the rolling elements in the bearing could cause peeling on these surfaces, thereby resulting in a decrease in the durability of the rolling bearing.
Therefore, in order to prevent the entry of foreign substances, a rolling bearing equipped with filters is proposed, in which a sealing ring attached to the rolling bearing is provided with filters. The sealing ring is an elastic sealing member made of an elastomeric material, wherein the sealing ring is provided with oil flow holes for allowing oil to pass therethrough, and wherein the oil flow holes are provided with filters configured to capture the foreign substances contained in the oil (for example, JP 6-323335 A and JP 2002-250354 A).